LONDON — Marathons have long been seen as the ultimate test of speed and stamina. The winner of last Sunday’s event in London, Eliud Kipchoge of Kenya, crossed the finish line in 2 hours 2 minutes 37 seconds — the second-fastest time ever for the 26.2-mile distance.
Behind him was an enthusiastic crowd of some 43,000 runners of varying abilities, many of whom were following official pacers carrying flags denoting an anticipated finishing time — with a cutoff of eight hours.
But some of those at the back of the pack said that what was supposed to be a cheerful celebration of running turned sour when cleanup crews hindered their progress and even insulted them.
Elizabeth Ayres, who was pacing a group expected to finish in seven and a half hours, said in a Facebook post that sewage collection trucks blocked the runners from crossing Tower Bridge, where they were expecting a keepsake photograph.
“We ended up having to weave through moving vehicles to get through!” she wrote.
Ms. Ayres posted photos showing an obstacle course of maintenance vehicles, and areas where course markers had already been removed. She said her group was told to move out of the way and run on the sidewalk, and water stations had packed up before they reached them. Cleaning crews and race marshals made demeaning comments as they went, she said.
“If you weren’t so fat, you could run,” and “this is a race, not a walk,” were among the comments, Ms. Ayres told the BBC on Thursday. She said she would “rather the race was canceled than people being spoken to like that.”
The director of the London Marathon, Hugh Brasher, apologized to Ms. Ayres and her fellow runners on Thursday. “We are absolutely determined to understand what went on,” he told the BBC. “It will take time to do it, but I can assure you that the investigation will be thorough and as a result of it changes will be made.”
The London race, like marathons around the world, has sought to become more accessible to casual and novice runners, bestowing medals on all finishers and encouraging people to take up exercise and train for the race. It has even collaborated with Guinness World Records to celebrate unconventional achievements at the race. The organization certified 38 records on Sunday, including the fastest marathon in a six-person costume, run in just under six hours.
Event organizers, however, have struggled at times to include the slowest participants, including those who walk most of the course. In the face of much skepticism and blowback from serious athletes, running at the back of the pack has become a global movement, embraced by organizers including in London.
One of the issues is how to minimize traffic disruption from road closings. London’s race snakes through the heart of a city of eight million people, and uses major roads and bridges, causing buses to be diverted and forcing motorists to find alternate routes.
“We have a cutoff of seven hours whereby we have to start reopening the road system,” Mr. Brasher told the BBC. “We are in one of the busiest capital cities in the world — we have a finite amount of time with which to get people on to the course.”
Organizers said that participants were warned about cutoff times. Those who ran at a pace of over seven hours would have to move to the sidewalk, the official rule book warned.
Ms. Ayres’s group, organizers said, had crossed the finish line more than eight hours after the beginning of the race’s “mass start” at 10:10 a.m. But with thousands of runners at each of three start points, those at the back often have a long wait before setting off. Ms. Ayres wrote on Facebook that her start time had been almost an hour later, at 11:04.
Races handle the delicate issue of time cutoffs in different ways. At the Seven Mile Bridge Run — coincidentally held in Marathon, Fla., although it isn’t a marathon — runners who haven’t finished in 90 minutes are picked up in yellow school buses. The Big Sur marathon in California forces runners off the course if they have not reached the 21.2-mile mark in 5 hours 5 minutes.
That may come as little consolation for Ms. Ayres and others who complained of their treatment in London. “I spent 26.2 miles being the only support for too many runners yesterday and I’m angry,” Ms. Ayres wrote on Facebook. “My heart breaks for every runner over seven hours who had absolutely none of the world renowned experience,” she added.
Still, she didn’t let the conditions defeat her, writing, “I finished in 7:28:47, bang within time!”